Can Custom Script copy a value from Sales Order to Delivery Note Item

Can I use a Custom script to achieve the following:

Delivery Note Item has a custom field called po_number

On the New Delivery Note, when I click From Sales Order, my delivery note gets populated from the chosen Sales Order.

I want my Custom Script to copy the tabSales Order.po_number to the tabDelivey Note Item.po_number custom field.

I achieved this in the past by patching the python source code, but this approach has numerous downsides.

-Jev

For the benefit of others; I ended up patching the update_item method in apps/erpnext/erpnext/selling/doctype/sales_order/sales_order.py.

I would still prefer to be able to do this with javascript in the future! :smile:

Full method after patch;

        def update_item(source, target, source_parent):
                target.base_amount = (flt(source.qty) - flt(source.delivered_qty)) * flt(source.base_rate)
                target.amount = (flt(source.qty) - flt(source.delivered_qty)) * flt(source.rate)
                target.qty = flt(source.qty) - flt(source.delivered_qty)
                target.po_number = source_parent.po_number